I do our posters in Indesign. Not cheap but does an excellent job. I then save them as PDFs and e-mail them to the gigs, if possible, this saves on ink, paper and postage and there's more chance of the venue displaying them. If I have to print them out, along with the gig guides, I do it on the printer that the band paid for using the ink / toner and paper that the band pays for. The band wants posters and gig guides, I don't mind designing them, as I know how, but I'll be buggered if I'm going to provide the paper, printer and ink as well.